Some conventional DC/DC converters control the amount of energy to be stored or released in a reactor by using ON/OFF operation of a semiconductor switch, thereby performing conversion to a higher voltage than that of a DC power supply. In addition, in response to a problem that the reactor is large and heavy, a technique is proposed which reduces a voltage applied to the reactor by using charge and discharge of a capacitor and reduces an inductance value needed for the reactor, thereby reducing the size and the weight of the reactor. In one of such techniques, a DC voltage conversion section is provided between a reactor L connected to a DC power supply, and a smoothing capacitor C0 for the output voltage, and the DC voltage conversion section has: a series circuit composed of a switching device series circuit having first and second switching devices S1 and S2 connected in series, and a diode series circuit having diodes D1 and D2 connected in series, such that the switching device S1, the switching device S2, the diode D1, and the diode D2 are connected in series in this order, the anode side of the diode D1 being connected to the second switching device S2; and a charge-discharge capacitor C1. The charge-discharge capacitor C1 is connected between the connection part between the diode D2 and the diode D1, and the connection part between the switching device S2 and the switching device S1. The connection part between the switching device S2 and the diode D1 is connected to the DC power supply via the reactor L. The series circuit and the smoothing capacitor C0 are connected in parallel. The charge-discharge capacitor C1 is charged via the diode D1 by the first switching device S1 being turned on. The charge-discharge capacitor C1 discharges via the diode D2 by the second switching device S2 being turned on. The discharge current is given to the smoothing capacitor C0. The switching devices S1 and S2 are alternately turned on, thereby obtaining a voltage two times as high as that of the DC power supply (for example, see Patent Document 1).